[CCR] Refactor stats APIs

* Changed the auto follow stats to also include follow stats.
* Renamed the auto follow stats api to stats api and changed its url path
  from `/_ccr/auto_follow/stats` `/_ccr/stats`.
* Removed `/_ccr/stats` url path for the follow stats api, which makes
  the index parameter a required parameter.

x-pack/plugin/ccr/qa/multi-cluster/src/test/java/org/elasticsearch/xpack/ccr/FollowIndexIT.java

@@ -102,8 +102,9 @@ public void testAutoFollowPatterns() throws Exception {
         }
 
         assertBusy(() -> {
-            Request statsRequest = new Request("GET", "/_ccr/auto_follow/stats");
-            Map<String, ?> response = toMap(client().performRequest(statsRequest));
+            Request statsRequest = new Request("GET", "/_ccr/stats");
+            Map<?, ?> response = toMap(client().performRequest(statsRequest));
+            response = (Map<?, ?>) response.get("auto_follow_stats");
             assertThat(response.get("number_of_successful_follow_indices"), equalTo(1));
 
             ensureYellow("logs-20190101");

x-pack/plugin/ccr/qa/rest/src/test/resources/rest-api-spec/test/ccr/follow_stats.yml

@@ -45,7 +45,7 @@
 
   # we can not reliably wait for replication to occur so we test the endpoint without indexing any documents
   - do:
-      ccr.stats:
+      ccr.follow_stats:
         index: bar
   - match: { indices.0.index: "bar" }
   - match: { indices.0.shards.0.leader_index: "foo" }

x-pack/plugin/ccr/qa/rest/src/test/resources/rest-api-spec/test/ccr/stats.yml

@@ -0,0 +1,11 @@
+---
+"Test stats":
+  - do:
+      ccr.stats: {}
+
+  - match: { auto_follow_stats.number_of_successful_follow_indices: 0 }
+  - match: { auto_follow_stats.number_of_failed_follow_indices: 0 }
+  - match: { auto_follow_stats.number_of_failed_remote_cluster_state_requests: 0 }
+  - length: { auto_follow_stats.recent_auto_follow_errors: 0 }
+  - length: { follow_stats.indices: 0 }
+

x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/Ccr.java

@@ -43,10 +43,10 @@
 import org.elasticsearch.xpack.ccr.action.TransportGetAutoFollowPatternAction;
 import org.elasticsearch.xpack.ccr.action.TransportUnfollowAction;
 import org.elasticsearch.xpack.ccr.rest.RestGetAutoFollowPatternAction;
-import org.elasticsearch.xpack.ccr.action.TransportAutoFollowStatsAction;
+import org.elasticsearch.xpack.ccr.action.TransportStatsAction;
 import org.elasticsearch.xpack.ccr.rest.RestAutoFollowStatsAction;
 import org.elasticsearch.xpack.ccr.rest.RestUnfollowAction;
-import org.elasticsearch.xpack.core.ccr.action.AutoFollowStatsAction;
+import org.elasticsearch.xpack.core.ccr.action.StatsAction;
 import org.elasticsearch.xpack.core.ccr.action.DeleteAutoFollowPatternAction;
 import org.elasticsearch.xpack.core.ccr.action.GetAutoFollowPatternAction;
 import org.elasticsearch.xpack.core.ccr.action.PutAutoFollowPatternAction;
@@ -164,7 +164,7 @@ public List<PersistentTasksExecutor<?>> getPersistentTasksExecutor(ClusterServic
                 new ActionHandler<>(ShardChangesAction.INSTANCE, ShardChangesAction.TransportAction.class),
                 // stats action
                 new ActionHandler<>(FollowStatsAction.INSTANCE, TransportFollowStatsAction.class),
-                new ActionHandler<>(AutoFollowStatsAction.INSTANCE, TransportAutoFollowStatsAction.class),
+                new ActionHandler<>(StatsAction.INSTANCE, TransportStatsAction.class),
                 // follow actions
                 new ActionHandler<>(PutFollowAction.INSTANCE, TransportPutFollowAction.class),
                 new ActionHandler<>(ResumeFollowAction.INSTANCE, TransportResumeFollowAction.class),

x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/action/TransportAutoFollowStatsAction.java → x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/action/TransportStatsAction.java

@@ -9,11 +9,13 @@
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.support.ActionFilters;
 import org.elasticsearch.action.support.master.TransportMasterNodeAction;
+import org.elasticsearch.client.Client;
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.block.ClusterBlockException;
 import org.elasticsearch.cluster.block.ClusterBlockLevel;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
 import org.elasticsearch.cluster.service.ClusterService;
+import org.elasticsearch.common.CheckedConsumer;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.license.LicenseUtils;
@@ -23,37 +25,40 @@
 import org.elasticsearch.xpack.ccr.Ccr;
 import org.elasticsearch.xpack.ccr.CcrLicenseChecker;
 import org.elasticsearch.xpack.core.ccr.AutoFollowStats;
-import org.elasticsearch.xpack.core.ccr.action.AutoFollowStatsAction;
+import org.elasticsearch.xpack.core.ccr.action.FollowStatsAction;
+import org.elasticsearch.xpack.core.ccr.action.StatsAction;
 
 import java.util.Objects;
 
-public class TransportAutoFollowStatsAction
-    extends TransportMasterNodeAction<AutoFollowStatsAction.Request, AutoFollowStatsAction.Response> {
+public class TransportStatsAction extends TransportMasterNodeAction<StatsAction.Request, StatsAction.Response> {
 
+    private final Client client;
     private final CcrLicenseChecker ccrLicenseChecker;
     private final AutoFollowCoordinator autoFollowCoordinator;
 
     @Inject
-    public TransportAutoFollowStatsAction(
+    public TransportStatsAction(
             Settings settings,
             TransportService transportService,
             ClusterService clusterService,
             ThreadPool threadPool,
             ActionFilters actionFilters,
             IndexNameExpressionResolver indexNameExpressionResolver,
             AutoFollowCoordinator autoFollowCoordinator,
-            CcrLicenseChecker ccrLicenseChecker
+            CcrLicenseChecker ccrLicenseChecker,
+            Client client
     ) {
         super(
             settings,
-            AutoFollowStatsAction.NAME,
+            StatsAction.NAME,
             transportService,
             clusterService,
             threadPool,
             actionFilters,
-            AutoFollowStatsAction.Request::new,
+            StatsAction.Request::new,
             indexNameExpressionResolver
         );
+        this.client = client;
         this.ccrLicenseChecker = Objects.requireNonNull(ccrLicenseChecker);
         this.autoFollowCoordinator = Objects.requireNonNull(autoFollowCoordinator);
     }
@@ -64,12 +69,12 @@ protected String executor() {
     }
 
     @Override
-    protected AutoFollowStatsAction.Response newResponse() {
-        return new AutoFollowStatsAction.Response();
+    protected StatsAction.Response newResponse() {
+        return new StatsAction.Response();
     }
 
     @Override
-    protected void doExecute(Task task, AutoFollowStatsAction.Request request, ActionListener<AutoFollowStatsAction.Response> listener) {
+    protected void doExecute(Task task, StatsAction.Request request, ActionListener<StatsAction.Response> listener) {
         if (ccrLicenseChecker.isCcrAllowed() == false) {
             listener.onFailure(LicenseUtils.newComplianceException("ccr"));
             return;
@@ -79,16 +84,20 @@ protected void doExecute(Task task, AutoFollowStatsAction.Request request, Actio
 
     @Override
     protected void masterOperation(
-            AutoFollowStatsAction.Request request,
+            StatsAction.Request request,
             ClusterState state,
-            ActionListener<AutoFollowStatsAction.Response> listener
+            ActionListener<StatsAction.Response> listener
     ) throws Exception {
-        AutoFollowStats stats = autoFollowCoordinator.getStats();
-        listener.onResponse(new AutoFollowStatsAction.Response(stats));
+        CheckedConsumer<FollowStatsAction.StatsResponses, Exception> handler = statsResponse -> {
+            AutoFollowStats stats = autoFollowCoordinator.getStats();
+            listener.onResponse(new StatsAction.Response(stats, statsResponse));
+        };
+        FollowStatsAction.StatsRequest statsRequest = new FollowStatsAction.StatsRequest();
+        client.execute(FollowStatsAction.INSTANCE, statsRequest, ActionListener.wrap(handler, listener::onFailure));
     }
 
     @Override
-    protected ClusterBlockException checkBlock(AutoFollowStatsAction.Request request, ClusterState state) {
+    protected ClusterBlockException checkBlock(StatsAction.Request request, ClusterState state) {
         return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA_READ);
     }
 }

x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/rest/RestAutoFollowStatsAction.java

@@ -12,15 +12,15 @@
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
 import org.elasticsearch.rest.action.RestToXContentListener;
-import org.elasticsearch.xpack.core.ccr.action.AutoFollowStatsAction;
+import org.elasticsearch.xpack.core.ccr.action.StatsAction;
 
 import java.io.IOException;
 
 public class RestAutoFollowStatsAction extends BaseRestHandler {
 
     public RestAutoFollowStatsAction(final Settings settings, final RestController controller) {
         super(settings);
-        controller.registerHandler(RestRequest.Method.GET, "/_ccr/auto_follow/stats", this);
+        controller.registerHandler(RestRequest.Method.GET, "/_ccr/stats", this);
     }
 
     @Override
@@ -30,8 +30,8 @@ public String getName() {
 
     @Override
     protected RestChannelConsumer prepareRequest(final RestRequest restRequest, final NodeClient client) throws IOException {
-        final AutoFollowStatsAction.Request request = new AutoFollowStatsAction.Request();
-        return channel -> client.execute(AutoFollowStatsAction.INSTANCE, request, new RestToXContentListener<>(channel));
+        final StatsAction.Request request = new StatsAction.Request();
+        return channel -> client.execute(StatsAction.INSTANCE, request, new RestToXContentListener<>(channel));
     }
 
 }

x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/rest/RestFollowStatsAction.java

@@ -21,7 +21,6 @@ public class RestFollowStatsAction extends BaseRestHandler {
 
     public RestFollowStatsAction(final Settings settings, final RestController controller) {
         super(settings);
-        controller.registerHandler(RestRequest.Method.GET, "/_ccr/stats", this);
         controller.registerHandler(RestRequest.Method.GET, "/{index}/_ccr/stats", this);
     }
 

x-pack/plugin/ccr/src/test/java/org/elasticsearch/xpack/ccr/AutoFollowIT.java

@@ -19,7 +19,7 @@
 import org.elasticsearch.xpack.CcrIntegTestCase;
 import org.elasticsearch.xpack.ccr.action.ShardFollowTask;
 import org.elasticsearch.xpack.core.ccr.AutoFollowStats;
-import org.elasticsearch.xpack.core.ccr.action.AutoFollowStatsAction;
+import org.elasticsearch.xpack.core.ccr.action.StatsAction;
 import org.elasticsearch.xpack.core.ccr.action.DeleteAutoFollowPatternAction;
 import org.elasticsearch.xpack.core.ccr.action.PutAutoFollowPatternAction;
 
@@ -260,8 +260,8 @@ private void deleteAutoFollowPatternSetting() {
     }
 
     private AutoFollowStats getAutoFollowStats() {
-        AutoFollowStatsAction.Request request = new AutoFollowStatsAction.Request();
-        return followerClient().execute(AutoFollowStatsAction.INSTANCE, request).actionGet().getStats();
+        StatsAction.Request request = new StatsAction.Request();
+        return followerClient().execute(StatsAction.INSTANCE, request).actionGet().getAutoFollowStats();
     }
 
     private void createLeaderIndex(String index, Settings settings) {

x-pack/plugin/ccr/src/test/java/org/elasticsearch/xpack/ccr/action/AutoFollowStatsResponseTests.java

@@ -7,25 +7,28 @@
 
 import org.elasticsearch.test.AbstractStreamableTestCase;
 import org.elasticsearch.xpack.core.ccr.AutoFollowStats;
-import org.elasticsearch.xpack.core.ccr.action.AutoFollowStatsAction;
+import org.elasticsearch.xpack.core.ccr.action.FollowStatsAction;
+import org.elasticsearch.xpack.core.ccr.action.StatsAction;
 
 import static org.elasticsearch.xpack.ccr.action.AutoFollowStatsTests.randomReadExceptions;
+import static org.elasticsearch.xpack.ccr.action.StatsResponsesTests.createStatsResponse;
 
-public class AutoFollowStatsResponseTests extends AbstractStreamableTestCase<AutoFollowStatsAction.Response> {
+public class AutoFollowStatsResponseTests extends AbstractStreamableTestCase<StatsAction.Response> {
 
     @Override
-    protected AutoFollowStatsAction.Response createBlankInstance() {
-        return new AutoFollowStatsAction.Response();
+    protected StatsAction.Response createBlankInstance() {
+        return new StatsAction.Response();
     }
 
     @Override
-    protected AutoFollowStatsAction.Response createTestInstance() {
+    protected StatsAction.Response createTestInstance() {
         AutoFollowStats autoFollowStats = new AutoFollowStats(
             randomNonNegativeLong(),
             randomNonNegativeLong(),
             randomNonNegativeLong(),
             randomReadExceptions()
         );
-        return new AutoFollowStatsAction.Response(autoFollowStats);
+        FollowStatsAction.StatsResponses statsResponse = createStatsResponse();
+        return new StatsAction.Response(autoFollowStats, statsResponse);
     }
 }

x-pack/plugin/ccr/src/test/java/org/elasticsearch/xpack/ccr/action/StatsResponsesTests.java

@@ -23,6 +23,10 @@ protected FollowStatsAction.StatsResponses createBlankInstance() {
 
     @Override
     protected FollowStatsAction.StatsResponses createTestInstance() {
+        return createStatsResponse();
+    }
+
+    static FollowStatsAction.StatsResponses createStatsResponse() {
         int numResponses = randomIntBetween(0, 8);
         List<FollowStatsAction.StatsResponse> responses = new ArrayList<>(numResponses);
         for (int i = 0; i < numResponses; i++) {